Sensors are typically composed of a number of component parts at least some of which are of different materials and which are rigidly interconnected to one another. If the sensor is subject to a change in temperature, then thermal expansion or contraction of each component part will occur. Where the component parts have different coefficients of thermal expansion, as will often be the case where the component parts are of different materials, then stresses will typically be induced.
Micro-electromechanical systems (MEMS) technology has been used to create a number of sensor designs. For example, MEMS based accelerometers and gyroscopes are well known. Such devices typically comprise a substantially planar silicon layer anchored to a substrate of, for example, glass or silicon. Other components may also be anchored to the substrate, and differential thermal expansion, as mentioned above, between the said other components and the substrate may induce stresses in the silicon layer which, in turn, can impact negatively upon the operation of the sensor. For example, the bias or scale factor of the sensor may be impacted.
US2010/0072563 and WO2008/069394 describe sensor arrangements in which a sensor element is bonded to a substrate. In each case, the sensor element includes movable parts movable relative to fixed parts, and whilst only the fixed parts of the sensor element, not the entire surface of the sensor element, are bonded to the substrate, as several parts of the sensor element are bonded to the substrate, differential thermal expansion or contraction results in stresses being induced in the sensor element.
US2010/0251818 and US2010/0300201 describe an arrangement in which a resilient or compliant support is used to support a sensor element, accommodating differential thermal expansion.
US2003/0038415 describes a mounting arrangement for a sensor and which is compliant.
It is an object of the invention to provide a sensor in which the disadvantages outlined hereinbefore are overcome or are of reduced effect.